Multicarrier communications may be described as a communications technique in which multiple carriers or subcarriers are used to communicate information. As an example of multicarrier communications, Orthogonal Frequency Division Multiplexing (OFDM) may be described as a communications technique that divides a communications channel into a number of spaced frequency bands. In OFDM, a subcarrier carrying a portion of the user information may be transmitted in each band. In OFDM, each subcarrier may be orthogonal, differentiating OFDM from the commonly used frequency division multiplexing (FDM). An OFDM symbol may include, for example, a symbol transmitted simultaneously on each of the OFDM subcarriers during the OFDM symbol period. These individual symbols may be referred to as subcarrier symbols.
Some communication systems may include features that may adapt to some types of changing conditions. For example, some systems allow a data transmission rate to be adjusted based upon a detected transmission condition. However, some types of adaptive systems can be complex or expensive. A need exists for an improved adaptive system